Field of the Invention
An adjustable tension hinge for a door or gate.
Description of the Prior Art
Self-closing and self-opening gates are in common use, particularly in situations which require increased safety. In deed, it is generally mandatory to provide self-closing gates for swimming pool fences to prevent unsupervised access by small children in the event that other persons have forgotten to close the gate. Similarly, self-closing gates are often employed in households to secure stairways and other potentially hazardous areas.
Gates of this type generally include a helical spring-loaded hinge which produces a torque to bias the hinge towards the closed or open position. A problem which arises in relation to such gates is that they vary in dimension and weight, and so the spring tension in the hinge must be adjusted accordingly in order to have the gate close or open at appropriate speed.
Examples of prior art are described below.
U.S. Pat. No. 8,549,707 describes a hinge comprising a first hinge member including a body portion having a longitudinal axis about which a second hinge member is rotatable to move the hinge between an open position and a closed position. The body portion houses biasing means having an end fixed relative to the second hinge member engages an adjustment member fixed with respect to the first hinge member. The adjustment member includes a ratchet means to move the adjustment member in a first direction to increase the tension in the biasing means.
U.S. Pat. No. 5,584,100 discloses a hinge comprising a first hinge member and a second hinge member. The first hinge member comprises a cylindrical housing disposed between flange members formed on the second hinge member. A torsion spring is provided inside the cylindrical housing disposed in a recess at end of the cylindrical housing and the other end fits into a recess in a coupling element located at the other end of the cylindrical housing. The coupling element has a hexagonal engagement surface which engages a matching engagement surface in flange. By depressing the coupling element so that it is no longer in engagement with flange member, the coupling element can be turned so that its hexagonal external surface is in a different orientation with respect to the matching hexagonal surface of the flange when pressure on the coupling element is release.
US 2014/007520 shows a hinge comprising first and second hinges and coupling connecting the first and second hinge parts. The first and second hinges are rotatable relative to each other having a biasing member to impart a biasing force relative rotation of the hinge parts. The coupling comprises a first coupling portion movable to change the biasing force of the biasing member. The hinge further comprises a stop arrangement to limit the adjustment movement to thereby restrict change to the biasing force.
U.S. Pat. No. 244,185 relates to a door-spring of two leaves, a pintle having an elongated vertical recess or groove in its lower end, a ratchet-collar on the pintle and having a lug engaging the recess or groove in the latter. A stationary stop is disposed one of the hinge-leaves. The collar is connected to the coiled spring to rotate with, and slide vertically on, the pintle substantially as and for the purpose described.
U.S. Pat. No. 5,651,536 shows a door closer or hinge including an upper adjustable torsion spring/ratchet combination power to close the door and a lower adjustable rotary damper to control the door closing speed.
U.S. Pat. No. 4,073,038 discloses an adjustable tension spring to close a hinge after being rotated to an open position comprising a pair of notched ratchet-like members.
U.S. Pat. No. 8,683,654 describes an adjustable torque hinge including a torque adjustment member and spring combination. The outer end of the torque adjustment member includes a hexagonal adjustment hole to receive a hex key to adjust the torque force. The torque adjustment member can then release the torque spring to return the adjustable torque hinge to the original tension.
Australian patent 666491 describes a coupling element connected to a spring. The coupling element includes a head portion with a circular top section and a hexagonal intermediate section which engages a matching hexagonal engagement surface in an aperture of the spring housing. To adjust the spring tension, a tool is inserted into the slot and pressure is applied to disengage the coupling element so that it can be turned to a different orientation. A disadvantage of this arrangement is that it requires the simultaneous application of a linear force along the spring axis and a rotational force about the spring axis. This is a relatively unnatural movement which can cause inconvenience to the installer.
Additional examples of the prior are found in U.S. Pat. No. 244,185; U.S. Pat. No. 255,938; U.S. Pat. No. 308,337; U.S. Pat. No. 3,316,582; U.S. Pat. No. 3,735,724; U.S. Pat. No. 4,817,242; U.S. Pat. No. 5,715,574 and U.S. Pat. No. 8,160,287.